Rotary dump bulk carrying rail car

ABSTRACT

A railway car body of the rotary dump type has side walls, bottom walls and end walls, the side walls having vertically upright upper portions and inwardly curving lower portions. Framing members embrace the side and end walls both along the top edges thereof and at the level where the side walls start to curve inwardly. The bottom wall includes a depressed centre section which is substantially semi-circular in vertical crosssection and merges smoothly with the inwardly curving lower portions of the side walls. The uitility of this car body resides in its simplicity of construction coupled with its light weight and the fact that its unloading characteristics are at least as good as those of conventional flat-sided transversely-framed open gondola cars.

United States Patent [1 1 Bailey et al.

ROTARY DUMP BULK CARRYING RAIL CAR Inventors: William Dale Bailey, Islington,

Ontario; Jan Zbigniew Tomaka, Outremont, Quebec, both of Canada Assignee: Alcan Research and Development Foreign Application Priority Data June 8,1971 Canada H5135 US. Cl. 105/406, 105/360 Int. Cl 361d 9/06, B61d 17/08 Field of Search 105/247, 358, 360, 406 R;

References Cited UNITED STATES PATENTS Proctor et al 105/360 [4 June 18, 1974 3,240,168 3/1966 Charles et al. 105/406 R 3,253,556 5/1966 Glaser et al.... 3,495,548 2/1970 Rollins 3,543,692 12/1970 Stark l05/358 Primary Examiner-Drayton E. Hoffman Attorney, Agent, or Firm-Christopher Robinson [5 7] ABSTRACT A railway car body of the rotary dump type has side walls, bottom walls and end walls, the side walls having vertically upright upper portions and inwardly curving lower portions. Framing members embrace the side and end walls both along the top edges thereof and at the level where the side walls start to curve inwardly. The bottom wall includes a depressed centre section which is substantially semi-circular in vertical cross-section and merges smoothly with the inwardly curving lower portions of the side walls. The uitility of this car body resides in its simplicity of construction coupled with its light weight and the fact that its unloading characteristics are at least as good as those of conventional flat-sided transversely-framed open gondola cars.

5 Claims, 3 Drawing Figures PATENTEDJHN 1 a 1914 SHEET 1 0F 2 PATENTEDJUM 18 mm SHEET 2 BF 2 FIGB.

BACKGROUND OF THE INVENTION This invention relates to a rotary dump bulk carrying railway car body.

Open gondola cars for rotary dump service have been traditionally built in the shape of a rectangular box attached to a full length centre sill and provided with closely spaced external frames which support the car floor, resist the outward pressure of lading on the walls, and enable, by their stabilizing effect, the car sides to act as longitudinal girders. Not only is this type of construction expensive in terms of material and manhours, but it results in an extremely heavy car body.

In order to overcome similar difficulties in covered hopper cars, tank hopper cars having curved side walls were developed. It was found that the lateral pressure of lading could be reacted, without recourse to closely spaced posts or frames, by membrane forces which arise in a curved panel subjected to normal pressure. The inherent stiffness of the curved side walls was found to be such that the stabilizing effect of widely spaced transverse bulk heads gave sufficient longitudinal girder strength to the side walls of the car. These tank hopper car bodies were much lighter than the conventional type and could be constructed more economically. An important disadvantage of this type of tank construction for rotary dump cars results from the fact that the top opening is necessarily appreciably narrower than the widest part of the car body. With a constricted opening of this nature,-the discharging of frozen loads during rotary dumping could lead to structural damage. An additional objection is the fact that, with a of this nature, it is necessary to employ at least two transverse bulk heads, thereby increasing to an undesirable extent the surface area wetted by the ladmg. r

The railway car body of the present invention retains the simplicity of construction and the desirable light weight of the tank type of car body construction yet provides unloading characteristics which are as good as or better than those of the conventional flat-sided transversely-framed open gondola car.

SUMMARY OF THE INVENTION The car body of the invention may be generally defined as a rotary dump bulk carrying railway car body comprising side walls, a bottom wall and end walls, the side walls having vertically upright upper portions and inwardly curving lower portions. Framing members embrace said side and end walls both along the top edges thereof and at the level where said side walls start to curve inwardly. The bottom wall includes a depressed centre section, said centre section being substantially semi-circular in vertical cross-section and merging smoothly with the inwardly curving lower portions of said side walls.

In the preferred construction, the bottom wall includes a flat shear plate at each end of the body and side sills which connect the shear plates to one another and extend along the side walls of the car body to brace the latter along the lines of juncture of the side walls with the depressed centre section of the bottom wall.

The presently preferred construction also includes transverse bulk heads having a butterfly wing shape connected to the side walls at points intermediate the end walls.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings which illustrate a presently preferred embodiment of the invention;

FIG. 1 is a perspective view;

FIG. 2 is a vertical cross-section taken along line 2-2 in FIG. I; and,

FIG. 3 is an end elevation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawings, reference numeral 10 generally indicates the side walls, while reference numeral 11 indicates the end walls. Each side wall 10 is made up of an upper vertically upright flat portion 12 and a lower inwardly curving portion 13. The bottom wall is made up of three parts. Two of these parts are a horizontally dis posed shear plate 14 located at one end of the car body and another such shear plate 15 located at the opposite end of the body. The third part is a depressed centre section 17 disposed between the shear plates 14 and 15. This centre section 17 has upwardly divergent end walls 18 connected to the shear plates 14 and 15. The longitudinally extending walls of the centre sectionl7 are substantially semi-circular in vertical cross-section, and the radius of the centre section is such that its longitudinal walls merge smoothly with the inwardly curving lower portions 13 of the cars side walls 10.

The end walls 11 of the car body are also upwardly divergent and are braced to resist the lading forces by triangular stiffener plates 19. Side sills 20 extend longitudinally along the edges of each shear plate 14 and 15 and brace the walls of the car body along the lines of juncture of the inwardly curved side wall portions 13 with the depressed centre section 17 of the bottom wall.

Framing members, generally indicated by reference numeral 21, extend along the top edges of both the side walls 10 and the end walls 11. Parallel framing members 22 embrace the outside of the side walls 10 and the end walls 11 and are located at the level where the side walls start to curve inwardly, i.e. the lines of juncture of parts 12 and 13 of the side walls 10. The framing members 22 which embrace the end walls 11 may be discontinuous, i.e., may not extend completely across their respective end walls 11. To provide local stiffening at points where the rotary dumper clamps apply a downward force to the car body vertical members 23 are added between the framing members 21 and 22.

Two transverse bulk heads 24 are provided to brace the side walls 10. Each bulk head comprises a plate 25 which is centrally cut away so as to result in a butterfly wing shape. The plates 25 are braced by means of crossed stiffening arms 26 and 27 located on opposite sides of the plate 25, each crossed arm extending between one of the side sills 20 and the longitudinal portion of the upper rectangular framing member 21 associated with the opposite side wall.

Stub sills 28 extend longitudinally along the bases of each of the shear plates 14 and 15 in the region of the longitudinal centre line of each plate and are braced by the triangular end wall stiffener plates 19. Conventional rail mounting trucks 29 are connected to the stub sills 28 and conventional draft gears and couplers (not shown) are mounted between the stub sills 28 and undemeath the shear plates 14 and 15. Bolster beams 30 extend transversely along the bases of the shear plates 14 and 15 in the region of the end walls 11.

In the illustrated embodiment the framing members 21 and 22 are designed as continuous beams spanning between the end walls and over the internal bulk heads. The use of side walls of compound cross-section consisting of the flat upper portions 12 and the inwardly curved lower portions 13 results in a construction in which a large proportion of the lateral pressure of the lading is reacted by membrane forces in the curved walls, thus reducing the lateral bending moments in the horizontal frame members 21 and 22. The width, length, and radius of curvature of the portions 12 and 13 making up the side walls should be so related to one another that critical shear stresses in the flat upper wall portions 12 will be approximately equal to the critical shear stresses in the curved lower portions 13.

The bufferfly shaping of the plates 25 acts to reduce the resistance to flow of lading when the car is being unloaded. It also, of course, results in a weight saving. Additionally, the use of the crossed stiffening arms 26 and 27 located on opposite sides of the bulk head plate 25 avoids the difficulty and expense associated with cross joints. The cross-section of arms 26 and 27 is given a downwardly converging taper whereby resistance to the flow of lading is minimized. The crosssection of the car body is defined, and the side walls of the car body are tied together, by means of the end walls and of the two minimum area butterfly-shaped bulk heads. The car body is built without central sill, thus effecting a further reduction in weight. It is found that sufficient longitudinal strength is provided in the car body by the following elements acting in combination: side sills 20; shear plates 14 and stub sills 28; and triangular end wall stiffeners 19 which brace the stop sills against rotation. The stub sills are braced against rotation by the triangular end wall stiffeners 19.

It will be appreciated from the foregoing that a railway car body has been provided which is of simple construction and light weight yet has good unloading characteristics even when its load has been frozen.

What we claim as our invention is:

l. A rotary dump bulk carrying railway car body comprising side walls, a bottom wall and end walls, the side walls having vertically upright upper portions and inwardly curving lower portions, framing members embracing said side and end walls both along the top edges thereof and along the lines where said side walls start to curve inwardly, said bottom wall including a depressed center section, said center section being substantially semi-circular in vertical cross-section and merging smoothly with the inwardly curving lower portions of said side walls, said bottom wall including a flat sheer plate at each end of said body, side sills connected to said sheer plates and extending along the side walls of said body to brace the latter along the lines of juncture of said side walls with said depressed center section of said bottom wall, at least one transverse bulk head connected to said side walls at points intermediate the end walls, said bulk head including crossed stiffening arms extending between said side sills and said framing member which extends along the top edges of said side walls.

2. A railway car body as defined in claim 1, wherein said bulk head is centrally reduced so as to have a butterfly wing shape whereby to present minimum resistance to flow of lading.

3. A railway car body as defined in claim 1, in which a large proportion of the lateral pressure of the lading is reacted by membrane forces in said side walls.

4. A railway car body as defined in claim 1, in which the critical shear stresses in the upright portions of the side wall are approximately equal to those in the lower inwardly curved portions and a large proportion of the lateral pressure of the lading is reacted by membrane forces in said side walls.

5. A railway car body as defined in claim 1, in which longitudinally extending stub sills are located beneath said sheer plates. 

1. A rotary dump bulk carrying railway car body comprising side walls, a bottom wall and end walls, the side walls having vertically upright upper portions and inwardly curving lower portions, framing members embracing said side and end walls both along the top edges thereof and along the lines where said side walls start to curve inwardly, said bottom wall including a depressed center section, said center section being substantially semi-circular in vertical cross-section and merging smoothly with the inwardly curving lower portions of said side walls, said bottom wall including a flat sheer plate at each end of said body, side sills connected to said sheer plates and extending along the side walls of said body to brace the latter along the lines of juncture of said side walls with said depressed center section of said bottom wall, at least one transverse bulk head connected to said side walls at points intermediate the end walls, said bulk head including crossed stiffening arms extending between said side sills and said framing member which extends along the top edges of said side walls.
 2. A railway car body as defined in claim 1, wherein said bulk head is centrally reduced so as to have a butterfly wing shape whereby to present minimum resistance to flow of lading.
 3. A railway car body as defined in claim 1, in which a large proportion of the lateral pressure of the lading is reacted by membrane forces in said side walls.
 4. A railway car body as defined in claim 1, in which the critical shear stresses in the upright portions of the side wall are approximately equal to those in the lower inwardly curved portions and a large proportion of the lateral pressure of the lading is reacted By membrane forces in said side walls.
 5. A railway car body as defined in claim 1, in which longitudinally extending stub sills are located beneath said sheer plates. 